Needle securing device for talking machines



April 18, 1933. A. M. a. CHARLIN 1,904,403

NEEDLE SECURING DEVICE FOR TALKING MACHINES Filed May 29, 1930 Fig. I

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Patented Apr. 18, 1933 UNITED STATES ANDRE MARIE BERNARD CHARLIN', OFPARIS, FRANCE NEEDLE SECURING DEVICE FOR TALKING MACHINES Applicationfiled Kay 29, 1930, Serial No.

The machines used heretofore for playing acoustic records and comprisinga needle or the like part the free end of which engages the recordgroove and the basis of which is connected with the vibratingreproducing parts shows the following serious drawback: the needleenters usually through its basls inside a sleeve inside which it isfastened by a set-screw; the part of the needle between this screw andthe free end of the said needle shows a certain yieldingness andconsequently' the displacement of this pointed end has for its effect tobend the needle while moving the vibratory parts, therefore thedisplacement of said vibratory part shall be smaller than that of thepointed end and the reproduction shall not be quite an exact one;moreover, the sleeve and the screw have a comparatively great inertiawhich imperils the accuracy of the reproduction and causes distortionthrough the greater damping of the higher vibrations than of the lower.

The object of my invention is a device for securing the needle whichremoves these drawbacks. It consists in that, in order to reduce theinertia, the part securin the needle does not vibrate therewith an thatin order to do away with the action of the fiexion of the needle, itsvibratory displacements are transmitted to the vibrating parts of thesound reproducer through a part connected with it very near its pointedend.

I have described hereinbelow and shown on appended drawing two forms ofexecution given by way of example of my invention.

Fig. 1 shows diagrammatically and partly in section a device accordingto my invention;

Fig. 2 shows a modification thereof.

The pointed end of the needle 1 engages an aperture provided in themovable part 2; its basis bears against a yielding stop 3 of rubber forinstance. This latter is borne by the non-vibrating part 6 of the soundbox or sound reproducer 7; a spring 4 acts by means of a rigid piece 8on the stop 3 so as to urge the needle through the hole in part 2. Thisspring may act either directly as shown in Fig. 1 or else as shown inFig. 2 through the agency ofa lever 5. It is thus apparent that 457,008,and in France August 14, 1929.

the small displacements to which the basis of the needle may besubmitted are damped by the stop 3 and are not transmitted to the rigidsupport 8 provided for this stop; the mass of the said support doestherefore not interfere with the vibratory movements and causesconsequently no damping.

The aperture provided in the plate 2 may be cylindrical as shown in Fig.l or conical as shown in Fig. 2; in all cases its size is such that theneedle cannot pass right through it and is stopped therein at a pointnear the pointed end, said end projecting however by a suflicient lengthfor it to be capable to engage the bottom of the record 9 without thepart 2 coming into contact with the record surface. It is apparent thatthe needle urged forwards by the spring 4, is slightly wedged againstthe aperture walls whereby its movements become integral with those ofpart 2 7 to which it transmits with the greatest accuracy the vibratorymovements caused by its passage through the record groove. Part 2 actsthrough 'a connection 10 on the vibrating part of the sound reproducer7.

It should also be well understood that the stylus holder deviceaccording to my invention can be used with any type of sound reproducingapparatus, for instance, with a pick-up.

' What I claim is:

1. In a stylus holding device of a sound reproducing apparatus includinga part to be vibrated, the combination of a member secured to said partand provided with a hole, a rigid stylus having a sharp tapering end anda maximum diameter greater than the inner. diameter of said hole, meansfor applying the tapering end of said stylus against the edge of saidhole so that it is wedged. therein with its point projecting from saidmember, and damping means interposed between the last mentioned meansand said stylus.

2. In a stylus holding device of a sound reproducing apparatus includinga part to be vibrated, the combination of a block secured to-said partand provided with a cylindrical hole having a part of restrictedsection, a rigid cylindrical stylus having a sharp tapering end adaptedto freely engage said hole, means for applying the tapering portion ofsaid stylus against the part of said hole that has a restricted sectionso that it is wedged therein with its sharp point projecting from saidblock, and damping means interposed between the last mentioned means andsaid stylus.

3. In a stylus holding device of a sound reproducing apparatus includinga part to be vibrated, the combination of a thin plate secured to saidpart and provided with a hole, a rigid stylus having a sharp taperingend and a. maximum diameter greater than the inner diameter of saidhole. means for applying the tapering portion of said stylus against theedge of said hole so that it is wedged therein with its sharp pointprojecting from said thin plate, and damping means interposed betweenthe last mentioned means and said stylus.

4. In a stylus holding device of a sound reproducing apparatus includinga stationary part and apart to be vibrated, the combination of a membersecured to said part to be vibrated and provided with a hole,- 'a rigidstylus having a sharp tapering end and a maximum diameter greater thanthe inner diameter of said hole, a rigid piece operatively connectedwith said stationary part so as to move in substantially coaxialrelation with said stylus, an elastic pad inserted between said pieceand said stylus, and a spring having one end operatively connected tosaid stationary part and the other end operatively connected to saidrigid piece for applying the tapering portion of said stylus againstsaid hole so that it is wedgei'l therein with its sharp point projectingfrom aid member.

In testimony whereof have atliXed my signature.

ANDRli MARIE BERNARD CHARLHN.

